JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <input type=checkbox>
    <label>Label <span>(selected)</span></label>
    <br/>
    <input type=checkbox>
    <label>Label <span>(selected)</span></label>
</form>

CSS

body { font-size: 200% }
.etykieta_wybrana { color: red }
label span { display: none }
label.etykieta_wybrana span { display: inline }

JavaScript

$('input:checkbox').change(function () {
    var $this = $(this);
    if( $this.is(':checked') ) {
        $this.next('label').addClass('etykieta_wybrana');
    } else {
        $this.next('label').removeClass('etykieta_wybrana');
    }
});